JPH0489511A - Measuring method of deformation of object by kinoform - Google Patents
Measuring method of deformation of object by kinoformInfo
- Publication number
- JPH0489511A JPH0489511A JP20472890A JP20472890A JPH0489511A JP H0489511 A JPH0489511 A JP H0489511A JP 20472890 A JP20472890 A JP 20472890A JP 20472890 A JP20472890 A JP 20472890A JP H0489511 A JPH0489511 A JP H0489511A
- Authority
- JP
- Japan
- Prior art keywords
- curved surface
- kinoform
- measured
- deformation
- reflected light
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims abstract description 12
- 239000004973 liquid crystal related substance Substances 0.000 claims abstract description 23
- 230000001678 irradiating effect Effects 0.000 claims 1
- 238000005259 measurement Methods 0.000 abstract description 9
- 238000012545 processing Methods 0.000 abstract description 4
- 230000003287 optical effect Effects 0.000 description 4
- 101100117236 Drosophila melanogaster speck gene Proteins 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
Landscapes
- Length Measuring Devices By Optical Means (AREA)
- Holo Graphy (AREA)
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野コ
本発明は、高精度の三次元形状物体の製作、測定等のた
めに、液晶パネルで実現したキノフォムにより物体の変
形を測定する方法に関するものである。[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a method for measuring the deformation of an object using a kinoform realized with a liquid crystal panel for the production and measurement of highly accurate three-dimensional objects. It is.
［従来の技術］
従来から、写真乾板を用いたホログラフィ干渉計は、微
小変位の高精度な検出技術として種々利用されている。[Prior Art] Holographic interferometers using photographic plates have been used in various ways as highly accurate detection techniques for minute displacements.
このホログラフィ干渉を利用する場合の最大の問題点は
、ホログラム記録のために写真乾板を必要とすることで
あり、さらに具体的には、写真乾板を用いて位相分布を
再現するために、露光、現像を行ってホログラムを作製
し、そのホログラムを光学システムにおける所要の位置
に再配置することである。The biggest problem when using this holographic interference is that a photographic plate is required for hologram recording, and more specifically, in order to reproduce the phase distribution using a photographic plate, exposure, The process involves developing a hologram and then repositioning the hologram at a desired position in an optical system.
このような作業は、非常に面倒であるばかりでなく、写
真乾板の現像、定着などに時間を要し、そのため−層簡
易で短時間に計測できるような手段が望まれていた。Such work is not only very troublesome, but also requires time for developing and fixing the photographic plate.Therefore, there has been a desire for a means that is simple and can measure layers in a short time.
［発明が解決しようとする課題］
本発明の技術的課題は、上述したホログラムを用いるこ
とな（、それに代えてキノフオームを用いることにより
、極めて簡易且つ短時間に任意の比較パターンを準備で
き、また比較測定も実時間で実行できるようにした物体
の変形測定方法を得ることにある。[Problems to be Solved by the Invention] A technical problem of the present invention is that any comparison pattern can be prepared extremely easily and in a short time by using a kinoform instead of the above-mentioned hologram, and The object of the present invention is to obtain a method for measuring the deformation of an object in which comparative measurements can also be performed in real time.
［課題を解決するための手段］
上記課題を解決するための本発明の測定方法は、計測対
象の三次元曲面にレーザ光を照射し、表面からの反射光
の位相分布を計測して、これと逆の位相分布を液晶パネ
ルにおいて再現することによりキノフオームを作製し、
このキノフオームに、変形が生じた上記三次元曲面ある
いは他の次元曲面からの反射光を入射し、両者の面形状
の差異を、発生する干渉縞パターンによって測定するこ
とを特徴とするものである。[Means for Solving the Problems] In order to solve the above problems, the measurement method of the present invention irradiates a three-dimensional curved surface to be measured with a laser beam, measures the phase distribution of the reflected light from the surface, and measures the phase distribution of the reflected light from the surface. By reproducing the opposite phase distribution on a liquid crystal panel, we created a kinoform,
The method is characterized in that reflected light from the deformed three-dimensional curved surface or another dimensional curved surface is incident on this kinoform, and the difference in surface shape between the two is measured based on the generated interference fringe pattern.
［作 用コ
物体の変形測定に際し、計測対象物体の三次元曲面の表
面からの反射光の位相分布を計測して、位相変調装置と
して機能する液晶パネルにそれと逆の位相分布を設定し
て、変形が生じた上記三次元曲面あるいは他の三次元曲
面からの反射光をそれに入射させると、発生する干渉縞
パターンによって、両者の面形状の差異を測定すること
ができる。[Operation] When measuring the deformation of an object, the phase distribution of the reflected light from the three-dimensional curved surface of the object to be measured is measured, and the opposite phase distribution is set on the liquid crystal panel that functions as a phase modulation device. When reflected light from the deformed three-dimensional curved surface or another three-dimensional curved surface is incident thereon, the difference in surface shape between the two can be measured from the generated interference fringe pattern.
［実施例］
以下に、図面を竪照して本発明の方法をさらに具体的に
説明する。[Example] The method of the present invention will be explained in more detail below with reference to the drawings.
従来から知られている通常の干渉計では、レーザ光をビ
ームスプリッタにおいて二分し、それぞれを鏡面で反射
させた後、再びそれらの波面を重ね合わせ、その際、一
方の波面にひずみを与えると、それが干渉縞となって現
われ、その干渉縞の形から上記ひずみを知ることができ
る。In conventionally known normal interferometers, laser light is split into two by a beam splitter, each reflected by a mirror surface, and then their wavefronts are superimposed again, and at that time, if one of the wavefronts is distorted, This appears as interference fringes, and the above distortion can be determined from the shape of the interference fringes.
一方、二分した光の一方を鏡面で、他方を２１］１１定
対象物体等の凹凸面で反射させると、その凹凸面では光
が複雑に散乱するので、両光の干渉の結果としではラン
ダムなスペック・パターンが生じることになる。しかし
、凹凸面での反射光の光路に何らかの手段を介在させて
、その反射光の波面を平面波面に戻すことができれば、
平面波面相互の干渉になり、上記凹凸面に若干の変形を
与えれば、両光の干渉の結果、干渉縞が生じることにな
り、その干渉縞の形から凹凸面の変形を知ることが可能
になる。On the other hand, if one of the two halves of the light is reflected on a mirror surface and the other on an uneven surface such as a 21] A spec pattern will result. However, if some means is interposed in the optical path of the reflected light from the uneven surface, and the wavefront of the reflected light can be returned to a plane wavefront,
If the plane wavefronts interfere with each other, and if the uneven surface is slightly deformed, interference fringes will occur as a result of the interference of both lights, and it is possible to determine the deformation of the uneven surface from the shape of the interference fringes. Become.
本発明は、上記凹凸面での反射光の波面を平面波面に戻
すための手段として、液晶パネルで実現したキノフオー
ム用いることを特徴とするものである。The present invention is characterized in that a kinoform realized by a liquid crystal panel is used as a means for returning the wavefront of the reflected light on the uneven surface to a plane wavefront.
第１図は、本発明の実施に用いる装置の構成を示すもの
で、レーザ光ｌをビームスプリッタ２において二分して
、その一方の光ビームｌａを計測対象物体の三次元曲面
３に照射し、そ゛の表面からの反射光をレンズ系４，５
及びその焦光点の絞り６を通し、さらに、以下に詳述す
る液晶パネル７を通して、ビーム結合器８に投射し、一
方、前記ビームスプリッタ２において二分した他方の光
ビーム１ｂは、レンズ系９．ｌＯ及び平面１ｕｌｌを介
してビム結合器８に投射し、そこで再び前記光ビーム１
ａの波面と重ね合わせ、レンズ系１２．１３を経て、Ｃ
ＣＤカメラ１４に投射するようにしている。FIG. 1 shows the configuration of an apparatus used to implement the present invention, in which a laser beam l is split into two by a beam splitter 2, one of the light beams la is irradiated onto a three-dimensional curved surface 3 of an object to be measured, The reflected light from that surface is passed through lens systems 4 and 5.
The light beam 1b, which is split into two by the beam splitter 2, is projected onto a beam combiner 8 through a diaphragm 6 at its focal point and a liquid crystal panel 7, which will be described in detail below. ．． 10 and the plane 1ull to the beam coupler 8, where again said light beam 1
It is superimposed with the wavefront of a, passes through lens system 12.13, and becomes C.
The image is projected onto the CD camera 14.
上記液晶パネル７は、通常の濃淡表示を行う液晶パネル
ではなく、位相変調装置として機能し、即ち、液晶分子
の状態による屈折率変化により光の位相が変調されるも
ので、一般にキノフオームと呼ばれるものである。The liquid crystal panel 7 is not a liquid crystal panel that displays normal gradation, but functions as a phase modulator, in other words, the phase of light is modulated by changes in the refractive index depending on the state of liquid crystal molecules, and is generally called a kinoform. It is.
変形測定に際しては、先ず、計測対象の三次元曲面３に
光ビーム１ａを照射し、ＣＣＤカメラ１４において反射
光の位相分布を計測して、コンピュタの処理により、そ
れと逆の位相分布を液晶パネル７によって再現させ、キ
ノフオームを作製する。次いで、この液晶パネル７によ
って実現したキノフオームに、適宜の変形を生じさせた
上記＝次元曲面３、あるいは他の三次元曲面に対して同
様に光ビーム１ａを照射した場合の反射光を入射し、そ
れをビーム結合器８において光ビームｌｂの波面と重ね
合わせ、レンズ系１２．１３を経て、ＣＣＤカメラ１４
に投射させる。その結果、ＣＣＤカメラ１４においては
干渉縞パターンを計測することができ、その干渉縞の形
から３次元曲面３の変形を測定することができる。When measuring deformation, first, the three-dimensional curved surface 3 to be measured is irradiated with the light beam 1a, the phase distribution of the reflected light is measured by the CCD camera 14, and the opposite phase distribution is measured by the liquid crystal panel 7 through computer processing. to create a kinoform. Next, reflected light when the light beam 1a is similarly irradiated on the =dimensional curved surface 3 or other three-dimensional curved surface that has been appropriately deformed is incident on the kinoform realized by this liquid crystal panel 7, It is superimposed on the wavefront of the light beam lb in the beam combiner 8, passes through the lens system 12.13, and then passes through the CCD camera 14.
to project. As a result, the CCD camera 14 can measure the interference fringe pattern, and the deformation of the three-dimensional curved surface 3 can be measured from the shape of the interference fringe.
このように、液晶パネル７で実現したキノフオームを用
いると、従来のホログラフィ干渉技術のように写真乾板
を用いる必要がなくなり、コンピュータ技術によってホ
ログラムに相当するものを容易に作製することが可能に
なる。即ち、コンピュータから液晶パネル７に任意の波
面を出力すると、それが液晶パネル７に位相パターンと
して設定され、コンピュータ制御で適当な波面を任意に
設定できるばかりでなく、他の波面との変換も極めて簡
単に、しかも短時間に行うことができる。In this way, by using the kinoform realized by the liquid crystal panel 7, there is no need to use a photographic plate as in conventional holographic interference technology, and it becomes possible to easily create something equivalent to a hologram using computer technology. In other words, when an arbitrary wavefront is output from the computer to the liquid crystal panel 7, it is set as a phase pattern on the liquid crystal panel 7, and not only can a suitable wavefront be arbitrarily set under computer control, but conversion with other wavefronts is also extremely easy. It can be done easily and in a short time.
また、ビームスプリッタ２において二分した光ビームの
一方を鏡面で、他方を測定対象物体等の凹凸面で反射さ
せると、両光の干渉の結果としてはランダムなスペック
・パターンが生じることは、さきに説明している。この
スペック・パターンにおけるスペック・サイズは、絞り
６によって過当に調整することができる。即ち、絞り６
を十分に絞るとスペック・サイズが大きくなるし、絞り
を大きく開くとスペック・サイズは小さくなる。Also, as previously mentioned, if one of the light beams split into two by the beam splitter 2 is reflected on a mirror surface and the other on an uneven surface of an object to be measured, a random spec pattern will occur as a result of interference between the two lights. Explaining. The speck size in this speck pattern can be overadjusted by the aperture 6. That is, aperture 6
If you close down the aperture sufficiently, the spec size will increase, and if you open the aperture wide, the spec size will decrease.
一方、液晶パネル７上には多数のピクセルが配列してい
るが、このビクセルの一つよりも上記スペック・サイズ
を太き（する必要がある。即ち、一つのスペックの中に
も位相分布があるので、その位相分布にも対応するよう
な位相分布を液晶パネル上に再現するには、例えば、少
なくとも二つのピックセルを一つのスペックに入れるな
どの配慮が必要になる。上記絞り６は、このような観点
からスペック・サイズを調整するために用いられるもの
である。On the other hand, a large number of pixels are arranged on the liquid crystal panel 7, but it is necessary to make the spec size thicker than one of the pixels.In other words, even within one spec, there is a phase distribution. Therefore, in order to reproduce a phase distribution corresponding to that phase distribution on the liquid crystal panel, consideration must be given, for example, to include at least two pixels in one spec. It is used to adjust specifications and sizes from such viewpoints.
次に、フリンジスキャニング法を導入しコンピュータに
よる高精度位相測定を行なう方法について説明する。Next, a method for performing high-precision phase measurement using a computer by introducing a fringe scanning method will be described.
さきに説明した従来の干渉計のように、レーザ光をビー
ムスプリッタにおいて二分し、それぞれを鏡面で反射さ
せた後、再びそれらの波面を重ね合わせ、その際、例え
ば一方の鏡面を傾斜させると、平行な干渉縞を生じさせ
ることができる。この場合において、一方の光路に全面
の均一な位相変調を行う位相変調装置を配置し、位相変
調が全面的にＯの場合の干渉縞の特定位置の強度を工２
、位相変調装置によりえ／３の均一な位相変調を行うこ
とにより干渉縞が１／３ピツチだけシフトした場合の同
位置の強度を■２．２え／３の均一な位相変調により干
渉縞がさらに １／３ピツチだけシフトした場合の同位
置の強度を１３として、コンピュータに記憶させる。こ
のような強度１１〜■３の三つのデータをコンピュータ
に記憶させておくと、任意の干渉縞の空間的な位相をコ
ンピュータにおいて測定することが可能になり、それに
伴って、計測対象物体からの反射光の波面の位相分布を
測定することが可能になる。Like the conventional interferometer described earlier, the laser beam is split into two by a beam splitter, each reflected by a mirror surface, and then their wavefronts are superimposed again, and at that time, for example, by tilting one mirror surface, Parallel interference fringes can be produced. In this case, a phase modulator that performs uniform phase modulation over the entire surface is placed in one optical path, and the intensity at a specific position of the interference fringes when the phase modulation is O over the entire surface is modified.
, the intensity at the same position when the interference fringes are shifted by 1/3 pitch by performing uniform phase modulation of 2.2 and 3 by uniform phase modulation of 2. Further, when the intensity is shifted by 1/3 pitch, the intensity at the same position is set to 13 and is stored in the computer. By storing these three data of intensities 11 to 3 in a computer, it becomes possible to measure the spatial phase of any interference fringe on the computer, and along with this, the spatial phase of any interference fringe can be measured on the computer. It becomes possible to measure the phase distribution of the wavefront of reflected light.
従って、計測対象の三次元曲面からの反射光とは逆の位
相分布を液晶パネルに再現してキノフオームを作製する
場合には、上記コンピュータにおける測定結果に基づい
て液晶パネル７に所要の位相分布を与えればよい。Therefore, when producing a kinoform by reproducing on the liquid crystal panel a phase distribution opposite to that of the reflected light from the three-dimensional curved surface to be measured, the required phase distribution is created on the liquid crystal panel 7 based on the measurement results on the computer. Just give it.
また、ビームスプリッタ２において二分した光ビームの
一方を平面鏡１１で、他方を測定対象物体等の三次元曲
面３で反射させたうえで干渉させると、ランダムなスペ
ック・パターンが生じ、前述したように、その反射光に
対応する位相分布を液晶パネル７において再現するが、
その場合に、液晶パネル７において、上記スペック・パ
ターンに対応する位相分布と全面的なＯ位相の変調とを
加えたもの、同じく全面的にえ／３だけ位相の変調を加
えたもの、さらに全面的に２ Ｌ／３だけ位相の変調を
加えたものを再現し、それらによって対象物体の変形時
に生じる変形干渉縞を計測して、コンピュータにおいて
必要な計算を行うことにより、非常に高精度の測定を行
うことが可能になる。In addition, when one of the light beams split into two by the beam splitter 2 is reflected by the plane mirror 11 and the other by the three-dimensional curved surface 3 of the object to be measured, etc., and then caused to interfere, a random spec pattern is generated, and as described above, , the phase distribution corresponding to the reflected light is reproduced on the liquid crystal panel 7,
In that case, in the liquid crystal panel 7, the phase distribution corresponding to the above spec pattern and the overall O phase modulation are added, the phase distribution is also added to the overall O phase modulation by E/3, and the entire surface is further added. By reproducing the phase modulated by 2 L/3 and measuring the deformation interference fringes that occur when the target object is deformed, and performing the necessary calculations on a computer, extremely high precision measurement can be achieved. It becomes possible to do this.
［発明の効果］
以上に詳述したように、従来のホログラフィ干渉による
方法では、写真乾板を用いて位相分布を再現していたた
め、現像・定着などに多くの時間を要していたが、本発
明の方法によれば、上記写真乾板に代えて液晶パネルに
より実現したキノフオームを用いているため、次のよう
な効果を期待することができる。[Effects of the invention] As detailed above, in the conventional method using holographic interference, the phase distribution was reproduced using a photographic plate, which required a lot of time for development and fixing. According to the method of the invention, since a kinoform realized by a liquid crystal panel is used in place of the photographic plate, the following effects can be expected.
■ 設定の高速化：電気信号によってすべての設定が実
現できるため、従来例に比して設定が著しく高速化され
る。■ Faster settings: All settings can be made using electrical signals, making settings much faster than conventional methods.
■ 測定の高速化：光学的方法ですべての処理ができる
ため、計算機処理などが不要になり、測定の高速化を実
現できる。■ Faster measurement: All processing can be done optically, eliminating the need for computer processing and enabling faster measurement.
■ 高精度化：光波長の１／３ｏの精度が実現できる。■ High precision: Accuracy of 1/3o of optical wavelength can be achieved.
第１図は本発明の変形測定方法を実施する装置の構成図
である。
１ ・・レーザ光、 ３・・三次元曲面、７・・液晶
パネル。FIG. 1 is a block diagram of an apparatus for implementing the deformation measuring method of the present invention. 1. Laser light, 3. Three-dimensional curved surface, 7. Liquid crystal panel.
Claims (1)
らの反射光の位相分布を計測して、これと逆の位相分布
を液晶パネルにおいて再現することによりキノフォーム
を作製し、このキノフォームに、変形が生じた上記三次
元曲面あるいは他の三次元曲面からの反射光を入射し、
両者の面形状の差異を、発生する干渉縞パターンによっ
て測定することを特徴とするキノフォームによる物体の
変形測定方法。1. Create a kinoform by irradiating a three-dimensional curved surface to be measured with a laser beam, measuring the phase distribution of the reflected light from the surface, and reproducing the opposite phase distribution on a liquid crystal panel. Injecting reflected light from the deformed three-dimensional curved surface or another three-dimensional curved surface into the form,
A method for measuring the deformation of an object using kinoform, which is characterized by measuring the difference in surface shape between the two based on the generated interference fringe pattern.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2204728A JPH0635929B2 (en) | 1990-08-01 | 1990-08-01 | Deformation measurement method of object by kinoform |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2204728A JPH0635929B2 (en) | 1990-08-01 | 1990-08-01 | Deformation measurement method of object by kinoform |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0489511A true JPH0489511A (en) | 1992-03-23 |
| JPH0635929B2 JPH0635929B2 (en) | 1994-05-11 |
Family
ID=16495332
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2204728A Expired - Lifetime JPH0635929B2 (en) | 1990-08-01 | 1990-08-01 | Deformation measurement method of object by kinoform |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0635929B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113465545A (en) * | 2021-06-30 | 2021-10-01 | 北京航空航天大学 | Three-dimensional measurement system based on high-speed LED array and measurement method thereof |
-
1990
- 1990-08-01 JP JP2204728A patent/JPH0635929B2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113465545A (en) * | 2021-06-30 | 2021-10-01 | 北京航空航天大学 | Three-dimensional measurement system based on high-speed LED array and measurement method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0635929B2 (en) | 1994-05-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Pedrini et al. | Shape measurement of microscopic structures using digital holograms | |
| US5467184A (en) | Method of large deformation measurement using speckle interferometry | |
| CN101451890A (en) | Three light wave transversal shearing interference apparatus and method for extracting differential phase | |
| CN107014784A (en) | A kind of measurement apparatus and method of scattering medium vector transmission matrix | |
| KR102552799B1 (en) | Optical measuring method and optical measuring system | |
| US6704112B1 (en) | Application of the phase shifting diffraction interferometer for measuring convex mirrors and negative lenses | |
| Xu et al. | Radial Hilbert transform for phase retrieval using two-wavelength three-frame phase-shifting interferometry | |
| US5071208A (en) | Two beam method for forming holographic optical elements free of secondary fringes | |
| CN111562089B (en) | Detection method for transmission phase of micro-optical element | |
| Li et al. | Simultaneous measurement of optical inhomogeneity and thickness variation by using dual-wavelength phase-shifting photorefractive holographic interferometry | |
| JPH0489511A (en) | Measuring method of deformation of object by kinoform | |
| TWI804128B (en) | Method and apparatus for measuring three-dimensional composite surface structure of object | |
| JP4023666B2 (en) | Dynamic shape measuring method and apparatus | |
| JP3233723B2 (en) | Phase pattern difference discriminator | |
| De Angelis et al. | Test of a conical lens using a two-beam shearing interferometer | |
| WO2005049840A2 (en) | Process and apparatus for measuring the three-dimensional shape of an object | |
| JPH0437362B2 (en) | ||
| Slangen et al. | Computer-aided interferometric measurements of drift and phase shifter calibration for digital speckle pattern interferometry | |
| JPH0619255B2 (en) | Interferometer and interferometer for aspherical surface measurement by optical spatial light modulator using liquid crystal | |
| Bhattacharya et al. | Phase shifting Interferometry and Wavefront Compensation using Liquid Crystal on Silicon (LCOS) Spatial Light Modulator (SLM) | |
| JPH04204032A (en) | Lens optical performance measuring device | |
| JP7503972B2 (en) | Shape measuring device | |
| JP3933856B2 (en) | Phase difference amplification system | |
| Bold et al. | Phase-difference amplification using a Sagnac interferometer | |
| JP2535732B2 (en) | Optical instrument aberration measurement method using hologram element |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EXPY | Cancellation because of completion of term |